7/122.5.1.4 Text-based Communication
Due to the limitations of existing systems, text-based communication is still commonly used mainly because it does not cause any bandwidth problems. This feature has both positive and negative implications on educational interactions. A positive implication is that students reflect more carefully when they have to articulate their arguments into written speech. Although the initial lack of typing skills is a problem, typing skills improve rather rapidly and are, indeed, very useful because even nowadays in many universities assignments have to be edited with a computer or typewriter.
Secondly, there is an important social aspect to be considered. Text-based communication lacks mechanisms for making social differentiation. Social status cues as well as physical cues such as gender, race or physical handicaps don't show up in written speech. However, sometimes you can read between the lines to find out something about a person. With the loss of physical cues comes, of course, the loss of important features of a face-to-face meeting. Gestures, voice intonation and facial expressions are lost in a text-based communication.
Recent technologies allow audio and video conferencing but this requires a degree of bandwidth which is, in most cases, currently unavailable. Though audio and video conferencing is feasible, it is not easy to store and structure recorded conferences. This is because it needs tremendously high storage space, and on the other hand sophisticated cutting tools are needed to remove unnecessary bits of audio or video. Since a lot of material is produced during an online course, search mechanisms would be appropriate. This is not a problem as long as you deal with text-based material, but becomes a very big problem when you think of audio or video.
Again, a combination of text-based and audio or video-based communication would be, in my opinion, appropriate. As far as synchronous communication is concerned, audio and video conferences provide for more natural means of communication. For asynchronous group discussion, text-based communication is useful because it can be stored and structured more easily.